samedi 22 avril 2017

The Orbital ATK Cygnus cargo ship was bolted into place on the International Space Station’s Earth-facing port of the Unity module at 8:39 a.m. EDT. Crew will ingress the spacecraft later today. The spacecraft will spend about three months on station before it is released in July for a destructive re-entry into the Earth’s atmosphere, disposing of several thousand pounds of trash.

The spacecraft’s arrival brings more than 7,600 pounds of research and supplies to support Expedition 51 and 52. Some of the research on board includes:

- In microgravity, cancer cells grow in 3-D, spheroid structures that closely resemble their form in the human body, enabling better tests for drug the efficacy. The ADCs in Microgravity investigation tests drugs designed as targeted cancer therapies called antibody-drug conjugates, developed by Oncolinx.

- The Solidification Using a Baffle in Sealed Ampoules (SUBSA) investigation originally was operated successfully aboard the station in 2002. Updated software, data acquisition, high definition video and communication interfaces will help advance understanding of the processes involved in semiconductor crystal growth. Investigations such as the CLYC Crystal Growth experiment will be conducted in the SUBSA Furnace and inserts. High-quality crystals are essential to a variety of applications, and a microgravity environment can produce better quality crystals.

- The Thermal Protection Material Flight Test and Reentry Data Collection (RED-Data2) investigation studies a new type of recording device that rides alongside a spacecraft as it reenters Earth’s atmosphere, recording data about the extreme conditions it encounters. Scientists, so far, have been unable to monitor those conditions on a large scale, and a better understanding could lead to more accurate spacecraft breakup predictions, better spacecraft designs, and materials capable of better resisting the extreme heat and pressure during the return to Earth.

Image above: Four spacecraft are parked at the station including the Orbital ATK Cygnus resupply ship, the Progress 66 cargo craft and the Soyuz MS-03 and MS-04 crew vehicles. Image Credit: NASA.

Prior to re-entry in late July, the Cygnus spacecraft will also host the third Spacecraft Fire Experiment, or SAFFIRE, to study how fire burns in microgravity. Data from these experiments will help inform the development of future crew spacecraft.

vendredi 21 avril 2017

The Expedition 51 crew is waiting for a space delivery mission after welcoming two new crewmates Thursday. Two astronauts are training for a resupply ship’s arrival as two other crew members are getting used to their new home in space.

The Cygnus cargo craft will arrive at the International Space Station early Saturday after a four-day trip to deliver new science experiments and crew supplies. Flight Engineer Thomas Pesquet with assistance from Commander Peggy Whitson will maneuver the Canadarm2 to reach out and capture Cygnus after its final approach. Finally, ground controllers will give the crew a break and remotely control the 57.7 foot robotic arm and install Cygnus to the Harmony module.

Image above: There are three spaceships docked at the International Space Station including two Soyuz crew ships and one Progress cargo ship. Image Credit: NASA.

NASA astronaut Jack Fischer is adapting to living in weightlessness for the first time, while his crewmate cosmonaut Fyodor Yurchikhin is beginning his fifth mission in space. The pair joined Expedition 51 Thursday morning just six-hours, 10-minutes after blasting off from Kazakhstan in the Soyuz MS-04 spaceship. They will stay in space until September before returning back to Earth with record-setting astronaut Whitson.

A new observation from NASA's Mars Reconnaissance Orbiter (MRO) captures the landing platform that the rover Opportunity left behind in Eagle Crater more than 13 years and 27 miles (or 44 kilometers) ago.

A series of bounces and tumbles after initial touchdown plunked the airbag-cushioned lander into the crater, a mere 72 feet (22 meters) across, on Jan. 25, 2004, Universal Time (Jan. 24, PST).

The scene includes Eagle Crater and Opportunity's nearby parachute and backshell, from the April 10, 2017, observation by MRO's High Resolution Imaging Science Experiment (HiRISE) camera.

This is the first color view from HiRISE of the Eagle Crater scene. Mars Reconnaissance Orbiter began orbiting Mars more than two years after Opportunity's landing. One of the first images from HiRISE in 2006 showed Opportunity at the rim of a much larger crater, Victoria, nearly 4 miles (about 6 kilometers) south of the landing site. The camera also recorded a monochrome view of Eagle Crater that year.

Eagle Crater is at the upper right of the new image. The lander platform's job was finished once the rover rolled off it. The parachute and backshell are at the lower left.

The smattering of small craters on a broad plain is a reminder of the amazement expressed in 2004 about Opportunity achieving a "hole-in-one" landing. When the lander's petals opened and Opportunity sent home its first look at its surroundings, it provided the first-ever close-by view of sedimentary rocks on Mars, in Eagle's rim.

Opportunity Mars Exploration Rover B landing platform

After leaving the lander and exploring Eagle Crater, the rover recorded a look-back view before departing the scene. Opportunity remains active more than 13 years later.

HiRISE, the most powerful telescope ever sent to Mars, is operated by the University of Arizona, Tucson, and was built by Ball Aerospace & Technologies Corp. of Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the MRO Project and Mars Exploration Rover Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it. JPL built the rover. For additional information about MRO visit: http://mars.nasa.gov/mro

(Highlights: Week of April 10, 2017) - Three crew members returned to Earth as NASA astronaut Peggy Whitson prepared for another round of a groundbreaking study on the International Space Station.

Whitson completed setup and updated the software for the Biomolecule Sequencer, a device that allows crew members to sequence DNA for various experiments in space. DNA sequencing is typically difficult and time-consuming and requires bulky and expensive equipment. This investigation tests a miniature sequencer in space to diagnose infectious diseases, identify microbes, and better understand the genetic changes experienced by astronauts while in space.

Image above: NASA astronaut Shane Kimbrough is flanked by his fellow space station crew mates – Russian cosmonauts Andrey Borisenko, left, and Sergey Ryzhikov– shortly before closing the hatch on their Soyuz capsule and returning to Earth from the space station on April 10. Image Credit: NASA.

Thanks to the sequencer samples with a short life-span would not need to be frozen and returned to a lab on Earth for analysis. Those samples can be examined on the station immediately after being collected, transmitting the data back to the ground, saving valuable research time. The real-time collection of genomic data will greatly improve scientific research in orbit. The small size of the Biomolecule Sequencer, approximately the size of a deck of playing cards, could also help doctors save lives in remote countries with minimal resources.

Whitson also installed a new hard drive into the locker for the re-flight of the Device for the study of Critical Liquids and Crystallization (DECLIC HTI-R) investigation. DECLIC HTI-R is an experiment that studies water near its critical point -- the point beyond which water loses its distinction between liquid and vapor and begins to behave as a dense gas. Salt tends to precipitate out from water at temperatures and pressures beyond this critical point. Understanding this behavior will assist designers in building extended-life, low-maintenance water oxidation reactors resistant to salt deposits and corrosion, providing a more environmentally friendly waste management system and reducing operating costs of power plants on Earth that use water for its working or coolant fluid. DECLIC is an investigation developed by the French Space Agency in Toulouse.

Whitson and ESA (European Space Agency) astronaut Thomas Pesquet completed a session for the Effects of Long-Duration Microgravity on Fine Motor Skills (Fine Motor Skills) investigation. Fine motor skills are crucial for successfully interacting with touch-based technologies, repairing sensitive equipment and a variety of other tasks. For NASA's Fine Motor Skills investigation, crew members perform a series of interactive tasks on a touchscreen tablet. The investigation is the first fine motor skills study to measure long-term microgravity exposure, different phases of microgravity adaptation, and sensorimotor recovery after returning to Earth gravity. The simple tasks developed for this investigation may have wide-reaching benefits for elderly patients, people with motor disorders or patients with brain injuries on Earth undergoing rehabilitation for conditions that impair fine motor control.

Thanks to social media and the power of citizen scientists chasing the northern lights, a new feature was discovered recently. Nobody knew what this strange ribbon of purple light was, so … it was called Steve.

ESA’s Swarm magnetic field mission has now also met Steve and is helping to understand the nature of this new-found feature.

Speaking at the recent Swarm science meeting in Canada, Eric Donovan from the University of Calgary explained how this new finding couldn’t have happened 20 years ago when he started to study the aurora.

Meet Steve

While the shimmering, eerie, light display of auroras might be beautiful and captivating, they are also a visual reminder that Earth is connected electrically to the Sun. A better understanding of the aurora helps to understand more about the relationship between Earth’s magnetic field and the charged atomic particles streaming from the Sun as the solar wind.

“In 1997 we had just one all-sky imager in North America to observe the aurora borealis from the ground,” said Prof. Donovan.

“Back then we would be lucky if we got one photograph a night of the aurora taken from the ground that coincides with an observation from a satellite. Now we have many more all-sky imagers and satellite missions like Swarm so we get more than 100 a night.”

And now, social media and citizen scientists also have an increasingly important role.

All-sky imagers and satellites

For instance, the Aurorasaurus website makes it possible for a large number of people to communicate about the aurora borealis. It connects citizen scientists to scientists and trawls Twitter feeds for instances of the word ‘aurora’. In doing so, it does an excellent job of forecasting where the aurora oval will be.

At a recent talk, Prof. Donovan met members of another social media group on Facebook: the Alberta Aurora Chasers. The group attracts members of the general public who are interested in the night sky and includes some talented photographers.

Looking at their photographs, Prof. Donovan came across something he hadn’t seen before. The group called this strange purple streak of light in the night sky captured in their photographs a ‘proton arc’ but for a number of reasons, including the fact that proton aurora are never visible, he knew this had to be something else.

However, nobody knew what it actually was so they decided to put a name to this mystery feature: they called it Steve.

While the Aurora Chasers combed through their photos and kept an eye out for the next appearances of Steve, Prof. Donovan and colleagues turned to data from the Swarm mission and his network of all-sky cameras.

Aurora borealis

Soon he was able to match a ground sighting of Steve to an overpass of one of the three Swarm satellites.

Prof. Donovan said, “As the satellite flew straight though Steve, data from the electric field instrument showed very clear changes.

“The temperature 300 km above Earth’s surface jumped by 3000°C and the data revealed a 25 km-wide ribbon of gas flowing westwards at about 6 km/s compared to a speed of about 10 m/s either side of the ribbon.

“It turns out that Steve is actually remarkably common, but we hadn’t noticed it before. It’s thanks to ground-based observations, satellites, today’s explosion of access to data and an army of citizen scientists joining forces to document it.

Swarm

“Swarm allows us to measure it and I’m sure will continue to help resolve some unanswered questions.”

Image above: NASA's Cassini spacecraft captured this view of planet Earth as a point of light between the icy rings of Saturn on April 12, 2017. Image Credits: NASA/JPL-Caltech/Space Science Institute.

A new image from NASA's Cassini spacecraft shows planet Earth as a point of light between the icy rings of Saturn.

The spacecraft captured the view on April 12, 2017, at 10:41 p.m. PDT (1:41 a.m. EDT on April 13). Cassini was 870 million miles (1.4 billion kilometers) away from Earth when the image was taken. Although far too small to be visible in the image, the part of Earth facing Cassini at the time was the southern Atlantic Ocean.

Image above: This cropped, zoomed-in version of the image makes it easier to see Earth's moon -- a smaller, fainter dot to the left of our planet's bright dot. Image Credits: NASA/JPL-Caltech/Space Science Institute.

Earth's moon is also visible nearby in a cropped, zoomed-in version of the image.

Cassini spacecraft animation

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.

A Long March 7 rocket lifted off Thursday with Tianzhou 1, an unpiloted refueling freighter heading for China’s Tiangong 2 mini-space station to conduct several months of robotic demonstrations, practicing for the assembly and maintenance of a future permanently-staffed orbital research complex.

Lighting up the evening sky with an brilliant orange glow for a crowd of tourists, foreign dignitaries and media representatives, the Long March 7 soared through scattered clouds atop 1.6 million pounds of thrust and headed southeast to line up with the orbital path of China’s Tiangong 2 space lab, where the cargo craft will dock some time Saturday.

The Long March 7 rocket had a one-minute launch opportunity Thursday timed for roughly the moment the orbital track of Tiangong 2 passed over the Wenchang launch base, which China began constructing in 2009 and inaugurated with two successful rocket flights last year.

According to the official CCTV+ television network, ground crews loaded about 45,000 gallons, or 170 cubic meters, of rocket-grade kerosene fuel into the Long March 7 rocket in the hours before Thursday’s launch. Cryogenic liquid oxygen was pumped aboard the launcher after the kerosene.

The Tianzhou 1 spacecraft fastened atop the Long March 7 rocket for Thursday’s launch carried several tons of fuel and new automatic docking equipment to test how China plans to resupply its planned space station, which could begin assembly in orbit as soon as next year with the launch of a massive core section.

At least two more modules will be added to create a 60-metric ton space station by 2022 capable of hosting three astronauts for stays of up to six months.

jeudi 20 avril 2017

The LHCb experiment finds intriguing anomalies in the way some particles decay. If confirmed, these would be a sign of new physics phenomena not predicted by the Standard Model of particle physics. The observed signal is still of limited statistical significance, but strengthens similar indications from earlier studies. Forthcoming data and follow-up analyses will establish whether these hints are indeed cracks in the Standard Model or a statistical fluctuation.

On April 18, in a seminar at CERN, the LHCb collaboration presented new long-awaited results on a particular decay of B0 mesons produced in collisions at the Large Hadron Collider. The Standard Model of particle physics predicts the probability of the many possible decay modes of B0 mesons, and possible discrepancies with the data would signal new physics.

The LHCb cavern (Image: Maximilien Brice/CERN)

In this study, the LHCb collaboration looked at the decays of B0 mesons to an excited kaon and a pair of electrons or muons. The muon is 200 times heavier than the electron, but in the Standard Model its interactions are otherwise identical to those of the electron, a property known as lepton universality. Lepton universality predicts that, up to a small and calculable effect due to the mass difference, electron and muons should be produced with the same probability in this specific B0 decay. LHCb finds instead that the decays involving muons occur less often.

While potentially exciting, the discrepancy with the Standard Model occurs at the level of 2.2 to 2.5 sigma, which is not yet sufficient to draw a firm conclusion. However, the result is intriguing because a recent measurement by LHCb involving a related decay exhibited similar behaviour.

While of great interest, these hints are not enough to come to a conclusive statement. Although of a different nature, there have been many previous measurements supporting the symmetry between electrons and muons. More data and more observations of similar decays are needed in order to clarify whether these hints are just a statistical fluctuation or the first signs for new particles that would extend and complete the Standard Model of particles physics. The measurements discussed were obtained using the entire data sample of the first period of exploitation of the Large Hadron Collider (Run 1). If the new measurements indeed point to physics beyond the Standard Model, the larger data sample collected in Run 2 will be sufficient to confirm these effects.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Research into crystal growth in microgravity was one of the earliest investigations conducted aboard the International Space Station and is continued to this day. The unique microgravity environment of space provides an ideal setting for producing crystals that are more perfect than their terrestrial-grown counterparts. The Crystal Growth of Cs2LiYCl6:Ce Scintillators in Microgravity (CLYC-Crystal Growth), a Center for the Advancement of Science in Space (CASIS)-sponsored investigation, will study the potential benefits of growing the CYLC crystal in microgravity.

The CLYC crystal is a special kind of multicomponent crystal system used to make scintillator radiation detectors, a device that is sensitive to both gamma rays and neutrons.

“It’s a spectroscopic crystal, which means, using this crystal, we can detect the presence and intensity of radiation, as well as identify which isotopes emit radiation by measuring the energy,” said Dr. Alexei Churilov, primary investigator and senior scientist at Radiation Monitoring Devices Inc. (RMD).

The CLYC crystal is produced as a commercial product by RMD and is largely used to detect and differentiate both harmful and harmless levels of radiation. The crystal’s main application is homeland security as a method of detected smuggled nuclear materials, but may also be used for oil and gas exploration, medical imaging, particle and space physics and scientific instruments.

However, the Earth-grown crystals have shown defects such as cracks, grain boundaries and inclusions, incidents which scientists like Churilov hope to eliminate by using the space station’s microgravity environment as a growth habitat.

Image above: Flight ampoules for CLYC Crystal Growth samples, to be transported to the International Space Station. Resulting crystals will be compared against on-ground samples to develop on-Earth techniques for crystal growth. Image Credit: Alexei Churilov.

Research has shown that many, though not all, crystals benefit from growth in microgravity. Although the reasoning behind this phenomena is still being investigated, research points to the lack of buoyancy-induced convection, which affects transport of molecules in the crystal.

“Our ultimate goal is to study the growth of CLYC in microgravity without the interference of convection and to improve the production of the crystal on Earth,” said Churilov.

The research for the CLYC Crystal Growth investigation will be conducted within the Solidification Using a Baffle in Sealed Ampoules Furnaces and Inserts (SUBSA Furnaces and Inserts). SUBSA helps researchers advance the understanding of processes involved in semiconductor crystal growth. It offers a gradient freeze furnace for materials science investigations. SUBSA was originally operated aboard the space station in 2002, the SUBSA hardware has been modernized and updated with data acquisition, high resolution video and communication interfaces.

Image above: CLYC crystals grown in on Earth often contain imperfections such as inclusions (left), cracks (middle) and grain boundaries (right). The goal is to understand their formation without the interference of convection to improve crystal growth on Earth. Image Credit: Alexei Churilov.

During the investigation, four crystal growth runs will be conducted aboard the space station and then in the ground-based SUBSA furnaces, giving researchers a view into the gravitational effect on their growth. Once the investigation is complete, the space-grown crystals will be compared against their counterparts on Earth and tested for imperfections and effectiveness as radiation detectors.

Although microgravity can’t be mimicked or reproduced on the ground, results from the investigation will provide information about which crystal methods to use on Earth, how to improve ampoule and furnace design and which crystal growth parameters to change in pursuit of a more perfect crystallization process.

CASIS Orbital ATK CRS-7 Payload Overview

Though the total weight of the CLYC Crystal Growth investigation is small, only a few kilograms together with packaging, the benefits can be immense as the data gathered during the investigation will be put to immediate use in the production of CLYC crystals.

Images above: NASA's Dawn spacecraft has revealed many landslides on Ceres, which researchers interpret to have been shaped by a significant amount of water ice. Shown are examples of Type I (left), Type II (middle) and Type III (right). Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

As NASA's Dawn spacecraft continues exploring Ceres, evidence mounts that the enigmatic dwarf planet retains a significant amount of water ice. A new study in the journal Nature Geoscience adds to this picture, showing how ice may have shaped the variety of landslides seen on Ceres today.

"Images from Dawn show that landslides, many of which are similar to those seen on Earth, are very common on Ceres, and further the case that Ceres has a lot of water ice involved in its structure," said Britney Schmidt, who led the study. She is an associate of the Dawn science team and assistant professor at Georgia Institute of Technology in Atlanta.

Types of Landslides

Schmidt and colleagues identified three types of landslides. Type I, which are relatively round and large, have thick "toes" at their ends. They look similar to rock glaciers and icy landslides on Earth. Type I landslides are mostly found at high latitudes on Ceres, which is also where the most ice is thought to reside just beneath the surface, suggesting they involve the most ice of any of the flow features. Three small Type 1 flows are found in Oxo Crater, a tiny bright crater in the northern hemisphere that hosts an ice deposit at the surface.

Type II features are often thinner and longer than Type I, and are the most common type of landslide on Ceres. The landslide deposits appear similar to those left behind by avalanches seen on Earth.

Ceres' Type III features may involve a brief melting of some of the ice within the soil-like regolith, causing the material to flow like mud before refreezing. These landslides are always associated with large impact craters, and may have formed when an impact event melts subsurface ice on Ceres. These features have similar appearances to ejected material from craters in the icy regions of Mars and on Jupiter's moon Ganymede.

"The locations of these different types of features reinforces the idea that the shallow subsurface of Ceres is a mixture of ice and rock, and that ice is most plentiful near the surface at the poles," Schmidt said.

Scientists were also surprised at just how many landslides have occurred on Ceres in general. About 20 to 30 percent of craters greater than 6 miles (10 kilometers) wide have some type of landslide associated with them. Such widespread "ground ice" features, which formed from of a mixture of rock and ice, had only been observed before on Earth and Mars.

Implications and Future Observations

Based on the shape and distribution of landslides on Ceres, study authors estimate that the ice in the upper few tens of meters of Ceres may range from 10 percent to 50 percent by volume.

"These kinds of flows are not seen on bodies such as Vesta, which Dawn studied from 2011 to 2012, because the regolith is devoid of water," said Carol Raymond, deputy principal investigator for the Dawn mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

Now in its extended mission phase, Dawn is using its ion engine to swivel the plane of its orbit around Ceres to prepare for observations from a new orbit and orientation. At the end of April, the spacecraft will be directly between the sun and the mysterious Occator Crater. In this geometry, Dawn may deliver new insights about the reflective material of Ceres' most famous "bright spot," the highly reflective center of Occator that has been named Cerealia Facula.

Dawn spacecraft at Ceres. Image Credit: NASA

The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: https://dawn.jpl.nasa.gov/mission

Three extraordinary planet-hunters have been recognized by TIME Magazine as this year’s top 100 most influential people: Natalie Batalha from NASA’s Ames Research Center in California’s Silicon Valley; Michael Gillon from the University of Liège in Belgium; and Guillem Anglada-Escudé from the Queen Mary University in London.

“It is truly exciting to see these planet-hunters among the other movers and the shakers of the world,” said Paul Hertz, Astrophysics division director at Headquarters in Washington. “These scientists have transformed the world’s understanding of our place in the universe, and NASA congratulates them for their well-deserved recognition.”

Natalie Batalha is the project scientist for NASA’s Kepler mission, the agency’s first dedicated planet-seeking mission tasked to determine whether worlds around other stars are common by looking for telltale dips in a star’s brightness caused by crossing, or transiting, planets. Thanks to Kepler, some scientists believe there is at least one world around every star in the sky. To date, Kepler has found more than 2500 planets, including a “bigger, older cousin” to Earth. In total, the Kepler spacecraft has found nearly 5100 possible planets. Batalha is the first woman at NASA to receive the Time 100 designation. Read more about Batalha’s accomplishments: https://www.nasa.gov/feature/ames/kepler/kepler-scientist-on-time-magazine-most-influential-list

Michael Gillon led the research that discovered seven Earth-size planets around TRAPPIST-1, a nearby ultra-cool dwarf star, approximately 40 light years away. He is the principal investigator of the TRAPPIST (“The Transiting Planets and Planetesimals Small Telescope”) project, a pair of telescopes in Chile and Morocco. In 2016, Gillon and colleagues announced three planets around TRAPPIST-1. Following up with NASA’s Spitzer Space Telescope and ground-based telescopes, Gillon and colleagues revealed in 2017 that there are actually seven planets around the star. Three of the seven worlds of TRAPPIST-1 are in the habitable zone, but any of them could have liquid water. The TRAPPIST-1 planets are some of the best targets for NASA’s upcoming James Webb Space Telescope to look for signs of habitability. Gillon is also the project leader and principal investigator of SPECULOOS, an upcoming ground-based telescope project for which TRAPPIST is the prototype. Read more about the TRAPPIST-1 discovery: Ultracool Dwarf and the Seven Planets http://orbiterchspacenews.blogspot.ch/2017/02/ultracool-dwarf-and-seven-planets.html

Guillem Anglada-Escudé led the research team who discovered Proxima b, a roughly Earth-sized exoplanet orbiting at a distance from its star that would allow temperatures mild enough for liquid water to pool on its surface. Proxima b orbits our nearest neighboring star Proxima Centauri just over four light-years from Earth. Proxima is the smallest member of a triple star system known as Alpha Centauri and is the closest star to Earth, besides our own sun. Read more about the European Southern Observatory-led Proxima b discovery.

Anglada-Escude’s research spans the realm of astrobiology, the study of the origin, evolution, distribution, and future of life in the universe. From 2009 to 2013, Anglada-Escude participated in a research study to learn more about life's chemical and physical evolution, from the interstellar medium, through planetary systems, to the emergence and detection of life. Learn more about the five-year research study supported by the NASA Astrobiology Institute: https://nai.nasa.gov/teams/can-5/ciw

NASA’s search for distant worlds continues with the Transiting Exoplanet Survey Satellite (TESS) launching in 2018, which will find new planets the same way Kepler does, but right in the stellar backyard of our solar system, covering 400 times the sky area. Webb will also launch in 2018, and peer into possible atmospheres of distant worlds to look for chemical hints of life.

New, American-made spacecraft flying to the International Space Station will play a big role in bringing resident crews back home to Earth, but their missions also include the ability to provide the orbiting laboratory with a temporary shelter in case of an emergency in space, or even a safe ride back to Earth with short notice.

The scenarios that would call for the spacecraft to operate as space-borne lifeboats have not occurred on the International Space Station before, but mission planners have long made sure they are prepared. An electrical issue or ammonia leak on the space station could call for astronauts to shelter inside a Commercial Crew Program spacecraft long enough to correct the problem.

A medical emergency requiring surgery on an astronaut would be a case demanding immediate evacuation from orbit to Earth, something the spacecraft supporting NASA missions would be equipped to handle. The Soyuz spacecraft handle the lifeboat capability needs for the station's current crews.

The need for a quick departure is more than a luxury for the space station. Every person on the orbiting complex has a specific emergency seat assigned throughout their mission that they have to get to if the need arises. Because there are limits to how many seats are available at a time, there also is a limit to how many residents can live and work there.

What does it mean for a spacecraft to be capable of serving as a lifeboat? As with all the needs for the new spacecraft, NASA outlined a list of requirements for designers to meet. For the most part, it means the spacecraft can be powered on quickly while docked to the station, even if it has been dormant for weeks or a couple of months. From air circulation fans to life support systems to thrusters, the spacecraft's systems will be designed to engage in minutes.

"Some systems will take longer to bring online, but the idea is to have spacecraft that astronauts can get into quickly for survival and then use to pull away from the station and come home if that is needed," said Kathy Lueders, manager of NASA's Commercial Crew Program. "Defining exactly what that means, and what the companies can do to make it real was the hard part. That's why we took a teamwork approach from the start and why we've treated this as a partnership."

Boeing and SpaceX, each working on their own crew-capable spacecraft — the CST-100 Starliner and Crew Dragon, respectively — are testing their systems thoroughly on Earth before they undergo evaluation in orbit without a crew aboard, and then on a short mission with astronauts. Their performances in space – without an actual emergency – are to be considered carefully before NASA certifies the companies to fly operational missions, which could see a spacecraft docked to the station for months at a time.

After a six-hour flight, NASA astronaut Jack Fischer and cosmonaut Fyodor Yurchikhin of the Russian space agency Roscosmos arrived at the International Space Station at 9:18 a.m. EDT Thursday where they will continue important scientific research.

The two launched aboard a Soyuz MS-04 spacecraft from the Baikonur Cosmodrome in Kazakhstan at 3:13 a.m. (1:13 p.m. Baikonur time), orbited Earth four times, and docked at the space station.

Expedition 51-52 Crew Welcomed Aboard the Space Station

The arrival of Fischer and Yurchikhin increased the station's crew complement to five. The two join Expedition 51 Commander Peggy Whitson of NASA and Flight Engineers Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency). The Expedition 51 crew members will spend more than four months conducting approximately 250 science investigations in fields such as biology, Earth science, human research, physical sciences and technology development.

Novitskiy and Pesquet will remain aboard the station until early June. Fischer and Yurchikhin are scheduled to remain aboard the station until September, along with Whitson, whose stay aboard the station was extended into Expedition 52 by an agreement recently signed between NASA and Roscosmos.

Images above: The Soyuz MS-04 rocket launches from the Baikonur Cosmodrome in Kazakhstan April 20, 2017, carrying Expedition 51 Soyuz Commander Fyodor Yurchikhin of Roscosmos and Flight Engineer Jack Fischer of NASA into orbit to begin their four and a half month mission on the International Space Station. Image Credits: NASA/Aubrey Gemignani.

The expanded Expedition 51 crew soon will conduct new science investigations arriving on Orbital ATK’s seventh NASA-contracted commercial resupply mission Saturday, April 22. Investigations arriving will include an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment and an advanced plant habitat for studying plant physiology and growth of fresh food in space. Another new investigation bound for the U.S. National Laboratory will look at using magnetized cells and tools to make it easier to handle cells and cultures, and improve the reproducibility of experiments. Cygnus also is carrying 38 CubeSats, including many built by university students from around the world, as part of the QB50 program. The CubeSats are scheduled to deploy from either the spacecraft or space station in the coming months.

Fischer and Whitson are scheduled to take part in the fifth spacewalk of the year on May 12. The pair’s main task will be to replace an avionics box on the starboard truss called an ExPRESS Logistics Carrier, a storage platform. The box houses electrical, and command and data routing equipment for science experiments and replacement hardware stored outside the station. The new avionics box is arriving aboard Orbital ATK’s Cygnus cargo craft on Saturday, April 22.

The crew members also are scheduled to receive one Russian Progress resupply mission delivering several tons of food, fuel, supplies and research.

For more than 16 years, humans have lived and worked continuously aboard the International Space Station, advancing scientific knowledge and demonstrating new technologies, making research breakthroughs not possible on Earth that will enable long-duration human and robotic exploration into deep space. A global endeavor, more than 200 people from 18 countries have visited the unique microgravity laboratory that has hosted more than 1,900 research investigations from researchers in more than 95 countries.

A Swedish-led team of astronomers used the NASA/ESA Hubble Space Telescope to analyse the multiple images of a gravitationally lensed type Ia supernova for the first time. The four images of the exploding star will be used to measure the expansion of the Universe. This can be done without any theoretical assumptions about the cosmological model, giving further clues about how fast the Universe is really expanding. The results are published in the journal Science.

Hubble’s view on lensing galaxy

An international team, led by astronomers from the Stockholm University, Sweden, has discovered a distant type Ia supernova, called iPTF16geu [1] — it took the light 4.3 billion years to travel to Earth [2]. The light from this particular supernova was bent and magnified by the effect of gravitational lensing so that it was split into four separate images on the sky [3]. The four images lie on a circle with a radius of only about 3000 light-years around the lensing foreground galaxy, making it one of the smallest extragalactic gravitational lenses discovered so far. Its appearance resembles the famous Refsdal supernova, which astronomers detected in 2015 (heic1525). Refsdal, however, was a core-collapse supernova.

Hubble’s view on lensed supernova

Type Ia supernovae always have the same intrinsic brightness, so by measuring how bright they appear astronomers can determine how far away they are. They are therefore known as standard candles. These supernovae have been used for decades to measure distances across the Universe, and were also used to discover its accelerated expansion and infer the existence of dark energy. Now the supernova iPTF16geu allows scientists to explore new territory, testing the theories of the warping of spacetime on smaller extragalactic scales than ever before.

Palomar’s view on iPTF16geu

“Resolving, for the first time, multiple images of a strongly lensed standard candle supernova is a major breakthrough. We can measure the light-focusing power of gravity more accurately than ever before, and probe physical scales that may have seemed out of reach until now,” says Ariel Goobar, Professor at the Oskar Klein Centre at Stockholm University and lead author of the study.

The SDSS view on iPTF16geu

The critical importance of the object meant that the team instigated follow-up observations of the supernova less than two months after its discovery. This involved some of the world’s leading telescopes in addition to Hubble: the Keck telescope on Mauna Kea, Hawaii, and ESO’s Very Large Telescope in Chile. Using the data gathered, the team calculated the magnification power of the lens to be a factor of 52. Because of the standard candle nature of iPTF16geu, this is the first time this measurement could be made without any prior assumptions about the form of the lens or cosmological parameters.

Keck’s view on lensed supernova

Currently the team is in the process of accurately measuring how long it took for the light to reach us from each of the four images of the supernova. The differences in the times of arrival can then be used to calculate the Hubble constant — the expansion rate of the Universe — with high precision [4]. This is particularly crucial in light of the recent discrepancy between the measurements of its value in the local and the early Universe (heic1702).

Schematic of strong gravitational lensing

As important as lensed supernovae are for cosmology, it is extremely difficult to find them. Not only does their discovery rely on a very particular and precise alignment of objects in the sky, but they are also only visible for a short time. “The discovery of iPTF16geu is truly like finding a somewhat weird needle in a haystack,” remarks Rahman Amanullah, co-author and research scientist at Stockholm University. “It reveals to us a bit more about the Universe, but mostly triggers a wealth of new scientific questions.”

Hubble Space Telescope

Studying more similarly lensed supernovae will help shape our understanding of just how fast the Universe is expanding. The chances of finding such supernovae will improve with the installation of new survey telescopes in the near future.

Notes:

[1] iPTF16geu was initially observed by the iPTF (intermediate Palomar Transient Factory) collaboration with the Palomar Observatory. This is a fully automated, wide-field survey delivering a systematic exploration of the optical transient sky.

[2] This corresponds to a redshift of 0.4. The lensing galaxy has a redshift of 0.2.

[3] Gravitational lensing is a phenomenon that was first predicted by Albert Einstein in 1912. It occurs when a massive object lying between a distant light source and the observer bends and magnifies the light from the source behind it. This allows astronomers to see objects that would otherwise be to faint to see.

[4] For each image of the supernova, the light is not bent in the same way. This results in slightly different travel times. The maximum time delay between the four images is predicted to be less than 35 hours.

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

This research was presented in a paper entitled “iPTF16geu: A multiply-imaged gravitationally lensed Type Ia supernova” by Goobar et al., which appeared in the journal Science.

While compiling an unprecedented census of one billion stars in our Galaxy, ESA's Gaia mission is also surveying stars beyond our Milky Way. A new image of M33, also known as the Triangulum galaxy, shows tens of thousands of stars detected by Gaia, including a small stellar census in its star-forming region NGC 604. This is a striking example of the mission's potential to detect and characterise stars in nearby galaxies.

Gaia's view of the M33 galaxy. Credit: ESA/Gaia/DPAC

Gaia, ESA's mission for precision astrometry, was launched in December 2013 and has been scanning the sky since 25 July 2014. While its goal is to survey one billion stars in our Milky Way galaxy – about one per cent of its total stellar content – the on-board detection system records a much wider selection of cosmic sources.

Even though the majority of objects detected by Gaia are Milky Way stars, the satellite has also been observing a wealth of stars that belong to other galaxies, providing an important database to study the stellar populations of galaxies beyond our own [1].

Observations of the M33 galaxy provide a clear demonstration of Gaia's prospects for extragalactic studies.

Located some 2.4 million light-years away, M33 is one of our neighbouring galaxies and is part of the Local Group, the assembly of galaxies that includes our Milky Way and the Andromeda galaxy. A spiral galaxy with less than one tenth the mass of the Milky Way or Andromeda, M33 is the third largest member of the Local Group and is thought to be a satellite galaxy of Andromeda.

A new image of the patch of sky where M33 is found, based on 26 scans performed between 7 and 9 December 2016, shows all points where Gaia detected one or more sources.

Gaia's detections correspond to about 40 000 of the galaxy's brightest stars, a small fraction of the total stellar population of M33, which amounts to roughly 40 billion stars. The high stellar density of this region means that Gaia can only detect a fraction of these extragalactic stars each time it scans this portion of the sky.

Very dense stellar fields – like external galaxies, as well as the densest portions of our Galaxy, such as Baade's Window [2] – are particularly challenging for Gaia. Even if very powerful, the data processing units on the satellite have a limit to the number of objects that can be observed per second without saturating the onboard computer. As time goes by, Gaia will survey these regions on many more occasions and with different scanning configurations, eventually recording more of the detected stars.

M33 hosts a well-known star-forming region, NGC 604, which is home to many newborn stars. With a density of about one million stars per square degree, NGC 604 is one such challenging region to observe.

A comparison between the Gaia detections in that region and a high-resolution image of this stellar nursery from the NASA/ESA Hubble Space Telescope shows that Gaia has detected about 150 individual stars in the NGC 604 region, which spans only about 0.55 square arcminutes in the sky. This number might not sound big in absolute terms, but it is impressive when considering that the observed field is about 2000 times smaller than the area covered by the full Moon in the sky, revealing that Gaia is able to detect a significant number of extragalactic stars.

This is even more remarkable given that Gaia's observed stars are automatic detections obtained by the satellite’s onboard computing system while scanning over the region, whereas the stars detected in astronomical images, such as those from Hubble, are the result of dedicated observations obtained by pointing at specific regions on the sky, which are later analysed by scientists.

ESA Science & Technology: An extragalactic star-forming region

Video above: From M33 to NGC 604. Click here for details and large versions of the video. Credits: ESA/Gaia/DPAC; ESA/Hubble & NASA.

With this quality of data, observations of stellar fields in Local Group galaxies like M33 will yield estimates of the position, parallax, and proper motion for a wealth of extragalactic stars – these will be published in the future Gaia data releases [3].

Notes:

[1] In addition to stars in the Milky Way and nearby galaxies, Gaia has been detecting distant galaxies and quasars – the bright cores of distant galaxies with an active black hole at their centre – as well as hundreds of thousands of asteroids and other small bodies in the Solar System.

[2] Baade's Window is an area on the sky toward the centre of the Milky Way with little contamination by interstellar dust, where the density of stars reaches up to three million per square degree.

[3] Due to the great distance of these extragalactic stars, they are mostly among the faintest sources detected by the satellite, requiring an especially meticulous analysis of the data in order to interpret them correctly.

This stunning cosmic pairing of the two very different looking spiral galaxies NGC 4302 and NGC 4298 was imaged by the NASA/ESA Hubble Space Telescope. The image brilliantly captures their warm stellar glow and brown, mottled patterns of dust. As a perfect demonstration of Hubble’s capabilities, this spectacular view has been released as part of the telescope’s 27th anniversary celebrations.

A sea of galaxies

Since its launch on 24 April 1990, Hubble has been nothing short of a revolution in astronomy. The first orbiting facility of its kind, for 27 years the telescope has been exploring the wonders of the cosmos. Astronomers and the public alike have witnessed what no other humans in history have before. In addition to revealing the beauty of the cosmos, Hubble has proved itself to be a treasure chest of scientific data that astronomers can access.

Wide-field image of NGC 4298 and NGC 4302 (ground-based image)

ESA and NASA celebrate Hubble’s birthday each year with a spectacular image. This year’s anniversary image features a pair of spiral galaxies known as NGC 4302 — seen edge-on — and NGC 4298, both located 55 million light-years away in the northern constellation of Coma Berenices (Berenice’s Hair). The pair, discovered by astronomer William Herschel in 1784, form part of the Virgo Cluster, a gravitationally bound collection of nearly 2000 individual galaxies.

The edge-on NGC 4302 is a bit smaller than our own Milky Way Galaxy. The tilted NGC 4298 is even smaller: only half the size of its companion.

Hubble Space Telescope

At their closest points, the galaxies are separated from each other in projection by only around 7000 light-years. Given this very close arrangement, astronomers are intrigued by the galaxies’ apparent lack of any significant gravitational interaction; only a faint bridge of neutral hydrogen gas — not visible in this image — appears to stretch between them. The long tidal tails and deformations in their structure that are typical of galaxies lying so close to each other are missing completely.

Pan on NGC 4298 and NGC 4302

Astronomers have found very faint tails of gas streaming from the two galaxies, pointing in roughly the same direction — away from the centre of the Virgo Cluster. They have proposed that the galactic double is a recent arrival to the cluster, and is currently falling in towards the cluster centre and the galaxy Messier 87 lurking there — one of the most massive galaxies known. On their travels, the two galaxies are encountering hot gas — the intracluster medium — that acts like a strong wind, stripping layers of gas and dust from the galaxies to form the streaming tails.

Zoom-in on NGC 4298 and NGC 4302

Even in its 27th year of operation, Hubble continues to provide truly spectacular images of the cosmos, and even as the launch date of its companion — the NASA/ESA/CSA James Webb Space Telescope — draws closer, Hubble does not slow down. Instead, the telescope keeps raising the bar, showing it still has plenty of observing left to do for many more years to come. In fact, astronomers are looking forward to have Hubble and James Webb operational at the same time and use their combined capabilities to explore the Universe.